I am not interested to know whether vivisection produces results that are profitable to the human race...The pain which it inflicts upon unconsenting animals is the basis of my enmity toward it, and it is to me sufficient justification without looking further.
—Mark Twain
couplet
In a poem, a pair of lines that are the same length and usually rhyme and form a complete thought. Shakespearean sonnets usually end in a couplet.